Introduction: Patients with hypertrophic cardiomyopathy (HCM) have lower peak oxygen uptake (VO2) than healthy peers. The mechanism of peak VO2 limitation in HCM has not been fully elucidated. Hypothesis: We assessed the hypothesis that resting echocardiographic parameters are predictive of peak VO2 in HCM. Methods: A retrospective review of adult HCM patients seen at a tertiary referral center from 2006-2012 was performed. Patients who underwent a comprehensive echocardiogram and cardiopulmonary treadmill exercise test within 1 week were included. Multivariate modeling was used to identify predictors of peak VO2 adjusting for age, sex, body mass index, beta blocker use, diabetes, smoking, systolic blood pressure, and obstructive HCM. Results: Five hundred and forty one patients met the inclusion criteria. The average age was 52 +/- 0.65 years, 62% were male, 78% had obstructive HCM, and 42% were NYHA class III or IV. Independent predictors of peak VO2 included averaged left ventricular (LV) longitudinal peak systolic strain (p<0.01) and right ventricular systolic pressure (RVSP) (p<0.01) (Figure 1). Obstructive versus non-obstructive HCM, grade of diastolic dysfunction, LV mass and wall thickness, left atrial volume index, right ventricular dysfunction and moderate or greater mitral or tricuspid regurgitation were not independent predictors of peak VO2. Conclusions: In conclusion, higher RVSP and less negative LV longitudinal peak systolic strain were moderate independent predictors of lower peak VO2. These findings confirm the hypothesis that resting echocardiographic parameters are predictive of peak VO2 in HCM. Further study of the relationship between echocardiographic findings and outcomes on cardiopulmonary exercise testing may help elucidate the mechanisms of exercise limitation in HCM.
Abstract 16958: ADHERE Risk Levels Predict 60-day Death and Re-hospitalization in Clinical Trial Patients with Acute Decompensated Heart Failure
Background: The Acute Decompensated Heart Failure National Registry (ADHERE) risk levels are a validated tool to assess the risk of in-hospital mortality in patients with acute decompensated heart failure (ADHF). The objective of this study is to determine if the risk levels predict 60-day outcomes in well-defined ADHF patients from NIH Heart Failure Clinical Research Network (HFCRN) trials. Methods: Our study cohort included 835 unique patients with ADHF enrolled in 3 NIH HFCRN trials: Diuretic Optimization Strategies Evaluation (DOSE), CARdiorenal REScue Study in Acute Decompensated Heart Failure (CARRESS-HF), and Renal Optimization Strategies Evaluation (ROSE). ADHERE risk level was assigned, as previously described, by baseline BUN (<43 vs. ≥43 mg/dL), Cr (<2.2 vs. ≥2.2, a modification from 2.75 mg/dL used in ADHERE due the Cr distribution in our study population), and systolic BP (≥ 115 vs < 115 mmHg). Baseline characteristics and outcomes were compared between risk levels. Results: Of the 835 patients enrolled in DOSE (308), CARRESS-HF (188), and ROSE (360), an ADHERE risk level could be assigned to 830, with 62 (8%) high, 521 (63%) intermediate, 247 (30%) low risk. Baseline characteristics (Table 1) and outcomes (Table 2), including combined 60-day death and re-hospitalization (hazard ratio 1.94, high risk versus low risk, p<0.01), varied by ADHERE risk level. Conclusion: ADHERE risk levels predict 60-day death and re-hospitalization rates in patients with ADHF. These results extend the utility of the ADHERE risk levels, by informing longer-term clinical decisions regarding advanced heart failure treatment, care transition strategies and clinical trial design.
Abstract 12302: Mortality and Readmissions After Heart Failure Hospitalization in a Community Based Cohort: Estimating Risk Using the Acute Decompensated Heart Failure National Registry (ADHERE) Classification and Regression Tree (CART) Algorithm
Background: The Acute Decompensated Heart Failure National Registry (ADHERE) Classification and Regression Tree (CART) algorithm is an accepted method to assess a heart failure (HF) patient’s risk of inpatient mortality based on the patient’s systolic blood pressure (≥115 vs. <115 mmHg), blood urea nitrogen (BUN; ≥43 vs. <43 mg/dL), and creatinine (≥2.75 vs. <2.75 mg/dL) at the time of admission. Whether the ADHERE CART algorithm identifies risk of longer term poor outcomes and is predictive in patients with systolic (EF < 50%) or diastolic (EF ≥ 50%) HF in the community is unclear. Methods: We identified all hospitalizations for a primary diagnosis of HF occurring between 2000-2013 in a community-based cohort living within 40 miles of Rochester, MN. Outcomes including length of stay, in-hospital mortality, 30 and 90 day post-discharge mortality and readmission for any cause at 30 and 90 days were compared across the ADHERE CART risk groups using logistic regression for the entire cohort and separately for systolic (EF < 50%) and diastolic (EF ≥ 50%) HF. Results: See Table. We examined 5,918 heart failure hospitalizations among 3,628 individual patients. Distribution of hospitalizations across the risk categories is shown in table. Length of stay, in-hospital mortality, 30 and 90 day mortality and 30 and 90 day readmission rates all increased with increasing ADHERE risk categories. Similar results were obtained separately for systolic and diastolic HF. Conclusion: The ADHERE CART algorithm is simple, uses data universally available on admission, and identifies groups that differ substantially in their post-discharge adverse outcomes regardless of HF type (systolic vs diastolic) in the community. The ADHERE CART algorithm may inform clinical decision regarding advanced HF treatments, end-of-life planning and care transition services in patients hospitalized for HF in the community.
Abstract 16775: Body Mass Index Predicts Exercise Capacity in Patients With Hypertrophic Cardiomyopathy
Introduction: Impaired peak VO2 and obesity are known predictors of morbidity and mortality in Hypertrophic Cardiomyopathy (HCM). The purpose of this study is to determine the degree of exercise impairment due to excess weight in patients with HCM. Methods: Adult HCM patients who underwent cardiopulmonary treadmill testing at our tertiary referral center from 2006 - 2012 and had consented to research participation were identified retrospectively. Percent predicted peak VO2 was calculated by the Astrand formula for men and the Jones formula for women which adjust for age and gender. Baseline echocardiographic features obtained within 1 week of exercise testing and % predicted peak VO2 were compared among four groups of patients stratified by body mass index (BMI). Results: 510 patients were identified, with a mean age at diagnosis of 44.3 ± 16.1 years, 186 (36.5%) female. Mean BMI at the time of cardiopulmonary exercise testing was 29.7 ± 5.3 and 227 (44.6%) patients had a BMI ≥ 30. Overweight and obese patients were older and were more likely to be male than their normal weight peers. However, there was no significant difference in ejection fraction (EF), resting left ventricular outflow tract gradient, right ventricular systolic pressure (RVSP), or septal thickness among the groups. HCM patients show impaired peak VO2 across all BMI groups. While peak VO2 increased progressively across BMI groups consistent with greater O2 demand generated by higher body weight, the adjusted peak VO2 in mL/kg/min fell progressively, indicating progressively greater performance impairment with increasing BMI despite similar degrees of cardiac impairment (p <0.0001) (Table 1). Conclusion: Increased BMI is associated with reduced exercise performance in a graded manner in HCM patients independent of cardiac impairment identified on echocardiography.
Inpatient Mortality Risk Scores and Postdischarge Events in Hospitalized Heart Failure Patients
Background The Acute Decompensated Heart Failure National Registry (ADHERE) and Get With The Guidelines (GWTG) registries have developed simple heart failure (HF) in-hospital mortality risk scores. We hypothesized that HF scores predictive of in-hospital mortality would perform as well for early postdischarge mortality risk stratification. Methods and Results In this single-center, community-based, retrospective study of all consecutive primary HF hospitalizations (6203 hospitalizations in 3745 patients) from 2000 to 2013, the ADHERE and GWTG risk scores were calculated from admission data. There were 176 (3.0%) and 399 (6.7%), 869 (14.7%), and 1272 (21.5%) deaths in-hospital and at 30, 90, and 180 days postdischarge, respectively. The GWTG but not ADHERE risk score was well calibrated for in-hospital mortality. Both the ADHERE (C statistic 0.66 and 0.67, 0.64, and 0.64) and GWTG (C statistic 0.74 and 0.73, 0.71, and 0.70) HF risk scores were similarly predictive of in-hospital and 30-, 90-, and 180-day postdischarge mortality. The ADHERE risk score identified 10% and the GWTG risk score identified 20% of hospitalizations where 180-day postdischarge mortality was 50%, a prognostic bench mark for hospice referral. In contrast, hospitalizations characterized as lowest risk by the ADHERE (57% of hospitalizations; 180-day mortality 16.2%) or GWTG score (20% of hospitalizations; 180-day mortality 8.0%) had substantially lower mortality (odds ratios high versus low risk of 5–8 [ADHERE] and 11–18 [GWTG] across time points; P <0.0001 for all). Conclusions The simple ADHERE and GWTG scores stratify hospitalized HF patients for both inpatient and early postdischarge mortality risk, allowing comprehensive risk assessment on admission.